I know it's late, but I finally got around to trying ska::flat_hash_map. For my application (lots of insertions and deletions) it's not quite as fast as F14, bu

I know it's late, but I finally got around to trying ska::flat_hash_map. For my application (lots of insertions and deletions) it's not quite as fast as F14, but the difference is fairly small. It's also much easier to incorporate than folly, since the entire thing is in a single header file.